Evaluating the Efficacy of PKU Synergy in Patients Expressing Phenylketonuria or Hyperphenylalaninemia

This study centres around a new one-a-day phenylalanine-free protein substitute for phenylketonuria patients. Fifty eligible adults (≥ 16 years) with proven phenylketonuria or hyperphenylalaninemia will be recruited and randomly allocated to one of two intervention arms (n = 25 per arm). Following a 3-day baseline period, and in addition to routine nutritional management, patients will receive either one sachet of the new protein substitute daily (intervention) or continue their usual dietary and/or protein substitute regimen (maximum of 1 protein substitute per day (equal to 20g protein equivalent) control) for 28 days.